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Modulation of rat heart alkaline phosphatase activity by drugs, hormones and nutrients
Author(s) -
Mota Ana,
Calhau Conceição,
Martel Fátima,
Martins Maria João
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a897-b
Subject(s) - alkaline phosphatase , chemistry , endocrinology , medicine , levamisole , hormone , in vivo , atenolol , pharmacology , enzyme , biochemistry , biology , microbiology and biotechnology , blood pressure
Alkaline phosphatase (ALP) has an important role in calcification (either in bone or in vascular compartment) and increased ALP expression seems to be associated with inflammatory processes. We aimed to investigate the effect of drugs, hormones and nutrients, with known cardiovascular effects and/or with effects upon ALP from other sources, upon rat ALP activity from heart homogenates. ALP activity was determined at pH 10.4 using p‐nitrophenylphosphate (in Tris‐buffer) as substrate. We showed, using specific activity inhibitors of ALP isoenzymes (levamisole and L‐phenylalanine) and by rt‐PCR, that rat heart has high ALP activity mainly of tissue‐nonspecific type but also but also of tissue‐specific, intestinal type II ALP. Marked inhibition of rat heart ALP activity (more than 75%) was observed with levamisole, theophylline and aspirin, and some inhibition (less than 50%) with L‐phenylalanine, beta‐estradiol, wine and beer. Corticosterone, progesterone and caffeine had no effect and propranolol and atenolol activated (up to 40 %) rat heart ALP activity. Results obtained with xanthines, beverages and steroid hormones were different from those obtained with ALP from other sources. We report for the first time that rat heart expresses intestinal ALP, type II. We suggest that ALP activity studies should take into account the source of ALP and that ALP pharmacological manipulation in vivo may constitute a target for the control of cardiovascular diseases. Support: FCT, POCTI, FEDER and Programa Comunitário de Apoio.